Fixing periodic boundary conditions

src/Decomposition/ie_ghost.hpp

src/Decomposition/ie_loc_ghost.hpp

src/Grid/grid_dist_id_iterator.hpp

src/Grid/grid_dist_id_iterator_sub.hpp

src/Grid/grid_dist_id_unit_test.hpp

src/Vector/vector_dist.hpp

src/Vector/vector_dist_unit_test.hpp